MvvmCross SubscriptionManager

SubscriptionManager.cs

public class SubscriptionManager
{
    private Dictionary<Type, MvxSubscriptionToken> subscriptions = new Dictionary<Type, MvxSubscriptionToken>();
    public IMvxMessenger Messenger { get; set; }

    public SubscriptionManager(IMvxMessenger messenger)
    {
        Messenger = messenger;
    }

    public void SubscribeToMessage<T>(Action<T> action) where T : MvxMessage
    {
        Unsubscribe<T>();
        subscriptions[typeof (T)] = Messenger.SubscribeOnMainThread(action);
    }

    /// <summary>
    /// Subscribes to a message and automatically unsubscribes after the first message is received.
    /// </summary>
    public void SubscribeToSingleMessage<T>(Action<T> action) where T : MvxMessage
    {
        SubscribeToMessage<T>(t => {
            Unsubscribe<T>();
            action(t);
        });
    }

    private void Unsubscribe<T>() where T : MvxMessage
    {
        var type = typeof (T);
        MvxSubscriptionToken value;
        if (subscriptions.TryGetValue(type, out value))
            Messenger.Unsubscribe<T>(value);
    }

    public void UnsubscribeAll()
    {
        var unsubscribeMethod = typeof (IMvxMessenger).GetRuntimeMethod("Unsubscribe",
            new[] { typeof (MvxSubscriptionToken) });
        foreach (var pair in subscriptions) {
            var genericMethod = unsubscribeMethod.MakeGenericMethod(pair.Key);
            genericMethod.Invoke(Messenger, new object[] { pair.Value });
        }
        subscriptions = new Dictionary<Type, MvxSubscriptionToken>();
        Messenger.RequestPurgeAll();
    }
}